In simple term, Baseline value is a value that you compare with the result. For example, Patient with high blood pressure goes to doctor. First thing that doctor will do is measure his blood pressure and record it in patients file (e.g BP =150). Next step: Doctor will prescribe a medication to Patient and ask him to visit again after one week. After one week of Medication, patient visits the doctor and doctor again checks his Blood Pressure (e.g 125). Next: doctor will compare this result (after one week of medication) with the result taken before medication was given (i.e. 150) and will come to the conclusion that “after one week of treatment there is a reduction in the Blood Pressure”. So, what he did: compare the result with the baseline value and find out the change from baseline Baseline Value: Last observation taken before giving the medication. Now, what is BOCF ? Now, consider this scenario: We have result of one subject. Where visit 2 is baseline value and you need to see the change from baseline after visit 9. How will you do it?